824 research outputs found
Separation of lymphocytes by electrophoresis under terrestrial conditions and at zero gravity, phase 3
Electrophoretic mobilities (EPM) of peripheral lymphocytes were studied from normal subjects, chronic hemodialysis patients and kidney transplant recipients. A technique to separate B lymphocytes and null cells from non-T lymphocyte preparation was developed. The experiments were designed to determine which subpopulation of the non-T lymphocytes is primarily affected and shows a decreased EPM in chronic hemodialysis patients and kidney transplant recipients
Control of atomic currents using a quantum stirring device
We propose a BEC stirring device which can be regarded as the incorporation
of a quantum pump into a closed circuit: it produces a DC circulating current
in response to a cyclic adiabatic change of two control parameters of an
optical trap. We demonstrate the feasibility of this concept and point out that
such device can be utilized in order to probe the interatomic interactions.Comment: 5 pages, 4 figures, uses epl2.cls, revised versio
Bioprocessing in Microgravity: Applications of Continuous Flow Electrophoresis to Rat Anterior Pituitary Particles
In this report we describe the results of a continuous flow electrophoresis (CFE) experiment done on STS-65 in which we tested the idea that intracellular growth hormone (GH) particles contained in a cell lysate prepared from cultured rat anterior pituitary cells in microgravity might have different electrophoretic mobilities from those in a synchronous ground control cell lysate. Collectively, the results suggested that CFE processing in microgravity was better than on earth; more samples could be processed at a time (6 x) and more variant forms of GH molecules could be resolved as well. We had also hoped to carry out a pituitary cell CFE experiment, but failure of the hardware required that the actual cell electrophoresis trials be done on earth shortly after Shuttle landing. Data from these experiments showed that space-flown cells possessed a higher electrophoretic mobility than ground control cells, thereby offering evidence for the idea that exposure of cultured cells to microgravity can change their net surface charge-density especially when the cells are fed. Collectively, the results from this pituitary cell experiment document the advantage of using coupled cell culture and CFE techniques in the microgravity environment
IVOA Recommendation: Vocabularies in the Virtual Observatory Version 1.19
This document specifies a standard format for vocabularies based on the W3C's
Resource Description Framework (RDF) and Simple Knowledge Organization System
(SKOS). By adopting a standard and simple format, the IVOA will permit
different groups to create and maintain their own specialised vocabularies
while letting the rest of the astronomical community access, use, and combine
them. The use of current, open standards ensures that VO applications will be
able to tap into resources of the growing semantic web. The document provides
several examples of useful astronomical vocabularies
Electronic and Magnetic Properties of Electron-doped Superconductor, Sm_{1.85}Ce_{0.15}CuO_{4-delta}
Temperature-dependent magnetization (M(T)) and specific heat (C_p(T))
measurements were carried out on single crystal Sm_{1.85}Ce_{0.15}CuO_{4-delta}
(T_c = 16.5 K). The magnetic anisotropy in the static susceptibility, chi
{equiv} M/H, is apparent not only in its magnitude but also in its temperature
dependence, with chi_{perp} for H{perp}c larger than chi_{parallel} for
H{parallel}c. For both field orientations, chi does not follow the Curie-Weiss
behavior due to the small energy gap of the J = 7/2 multiplet above the J = 5/2
ground-state multiplet. However, with increasing temperature, chi_{parallel}(T)
exhibits a broad minimum near 100 K and then a slow increase while
chi_{perp}(T) shows a monotonic decrease. A sharp peak in C_p(T) at 4.7 K
manifests an antiferromagnetic ordering. The electronic contribution, gamma, to
C_p(T) is estimated to be gamma = 103.2 (7) mJ/moleSmK^2. The entropy
associated with the magnetic ordering is much smaller than Rln2, where R is the
gas constant, which is usually expected for the doublet ground state of
Sm^{+3}. The unusual magnetic and electronic properties evident in M(T) and
C_p(T) are probably due to a strong anisotropic interaction between conduction
electrons and localized electrons at Sm^{+3} sites.Comment: 5 pages, 5 encapsulated postscript figures, late
Robust Digital Holography For Ultracold Atom Trapping
We have formulated and experimentally demonstrated an improved algorithm for
design of arbitrary two-dimensional holographic traps for ultracold atoms. Our
method builds on the best previously available algorithm, MRAF, and improves on
it in two ways. First, it allows for creation of holographic atom traps with a
well defined background potential. Second, we experimentally show that for
creating trapping potentials free of fringing artifacts it is important to go
beyond the Fourier approximation in modelling light propagation. To this end,
we incorporate full Helmholtz propagation into our calculations.Comment: 7 pages, 4 figure
Pedestrian Approach to the Two-Channel Kondo Model
We reformulate the two-channel Kondo model to explicitly remove the
unscattered charge degrees of freedom. This procedure permits us to move the
non-Fermi liquid fixed point to infinite coupling where we can apply a
perturbative strong-coupling expansion. The fixed point Hamiltonian involves a
three-body Majorana zero mode whose scattering effects give rise to marginal
self-energies. The compactified model is the N=3 member of a family of "O(N)"
Kondo models that can be solved by semiclassical methods in the large
limit. For odd , {\em fermionic} "Kink" fluctuations about the
mean-field theory generate a fermionic -body bound-state which
asymptotically decouples at low energies. For N=3, our semi-classical methods
fully recover the non-Fermi liquid physics of the original two channel model.
Using the same methods, we find that the corresponding O(3) Kondo lattice model
develops a spin-gap and a gapless band of coherently propagating three-body
bound-states. Its strong-coupling limit offers a rather interesting realization
of marginal Fermi liquid behavior.Comment: 17 pages, Revtex 3.0. Replaced with fully compiled postscript file
Artificial reefs: from ecological processes to fishing enhancement tools
info:eu-repo/semantics/publishedVersio
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